The present invention relates generally to housings for electronic components, and more particularly, to housings for RF distribution system components such as signal splitters, filters, couplers, or directional taps and signal attenuators.
RF-sealed enclosures are frequently required for housing various circuits and components utilized in signal distribution systems, such as signal splitters, couplers, or directional taps, attenuators and filters. Typically, such housings include a cast metal base member which defines an interior chamber within which the elements of the circuit or component are contained. Connections are typically established with input and output cables by means of conventional RF-type connectors, which may be mounted on and extend through one or more walls of the base member, or which may be formed integrally with the base member. An access aperture is typically provided on one wall of the base member to provide access to the interior chamber during manufacture to facilitate installation of resistors, capacitors and other elements of the circuit or component.
After assembly, the access aperture is covered with a cover plate to close the chamber. To prevent damage to or repositioning of circuit elements within the chamber, it is desirable that this cover plate be securely fastened in position over the aperture. Furthermore, to prevent RF leakage from the circuit elements, particularly of the 5 to 1000 MHz frequency range signals with which signal distribution system components are utilized, it is desirable that the cover plate be electrically bonded to the base member around its entire periphery.
In previous component housing constructions, various methods are utilized for securing the cover plate in place. One construction provides for a continuous peripheral solder bead between the housing and the cover. While providing good RF shielding, this has the disadvantage of requiring the time consuming manufacturing procedures of heating the housing and applying the solder bead.
Another construction provides a number of individual crimp engagements between the cover plate and the base member at selected locations around the periphery of the cover plate. A bead of epoxy is then applied around the periphery of the cover plate to seal the enclosure. This arrangement has the disadvantage of leaving gaps between the crimp locations in which the cover plate and the base member are not electrically connected, thereby providing the possibility for RF leakage from circuit elements within the housing, especially at VHF and UHF frequencies.
The present invention overcomes these deficiencies by providing a plurality of closely spaced electrical and mechanical engagements between the base member and the cover plate around the entire periphery of the cover plate.
Accordingly, it is a general object of the present invention to provide a new and improved RF shielded housing for RF components such as signal splitters, couplers, directional taps, filters, attenuators and the like.
It is a more specific object of the present invention to provide an RF-sealed housing of the type having a base member and a cover plate, and an improved means of electrical and mechanical attachment of the cover plate to the base member.
It is a further object of the present invention to provide an RF shielded electronic component housing of improved electrical and mechanical construction which is economical to manufacture.